One of several holiday movies with meaty roles for African-American actors, this biopic memorializes the owners and artists of Chess Records, the Chicago label that gave a home to major blues figures and helped push race music into the mainstream. The cast is drool-worthy: Jeffrey Wright as Muddy Waters, Mos Def as Chuck Berry, Eamonn Walker as Howlin' Wolf and Beyoncé Knowles as Etta James, all under the predatory paternalism of Adrien Brody's Leonard Chess. What a pity, then, that writer-director Darnell Martin reduces these pioneers to the sum of their foibles — greed, lust, drugs — and compacts each tragedy into bathos. Only Walker, parading a titanic menace, and Knowles, bitter and beautifully vulnerable, emerge from the clutter. Fans of the real Chess Records and its magnificent legacy have got a right to sing the blues. 12/5